1. Technical Field
The present invention relates to multitenant databases and, more particularly to tenant placement within multitenant databases when the tenants share data.
2. Description of the Related Art
In a cloud environment, to achieve economies of scale and elasticity, multiple tenants may be placed in the same computing node/machine. Given a set of tenants, such that each tenant consumes a certain amount of resource, the cloud service provider would like to use as few machines as possible to accommodate these tenants. When different tenants have no interactions, this can be considered as the Bin Packing problem.
However, as the cloud provides opportunities for the tenants to share data, it is likely the case that tenants would have interactions with one another. If one tenant shares its data with another tenant, it may be beneficial to place these two tenants on the same machine as, at the very least, it can save the cost of transferring the data between different machines. While the bin packing problem for multitenant databases without data sharing is relatively easy to solve, introducing data sharing causes the problem to become very difficult, not only to solve outright but even to approximate.